中文摘要：

采用富集培养技术从磺酰脲类除草剂污染土壤中筛选得到1株降解噻吩磺隆的细菌,命名为ZWS13.经形态特征和16S rRNA基因序列分析,初步鉴定为葡萄球菌属（Staphylococcus sp.）.采用HPLC研究了初始底物浓度、温度、接种量、pH等因素对菌株ZWS13降解噻吩磺隆的影响.结果表明,菌株ZWS13对噻吩磺隆的降解具有较广的底物浓度范围,在7 d内对初始浓度5.0-100.0 mg·L^-1噻吩磺隆的降解率达到60%以上;菌株ZWS13降解噻吩磺隆的较适pH为8.0,较适温度为40℃,较适接种量为1%;其中,菌株培养温度为40℃时,菌株在10 d内对50.0mg·L^-1噻吩磺隆的降解率达到99%以上.降解谱测定结果表明,菌株对烟嘧磺隆、吡嘧磺隆和甲磺隆亦具有良好的降解效果.采用HPLC-MS分析确定了菌株对噻吩磺隆的5个降解产物,推测菌株对噻吩磺隆的降解途径主要为磺酰脲桥C—N键的断裂、脱甲基作用或脱酯作用的甲基丢失及三嗪环的开裂.研究表明,菌株ZWS13能够有效地降解噻吩磺隆,具有生物修复噻吩磺隆污染的潜力.

英文摘要：

A bacterial strain ZWS13,which could degrade thifensulfuron-methyl（ TSM）,was isolated from sulfonylurea herbicides contaminated soil by culture enrichment. Strain ZWS13 was identified as Staphylococcus sp.,based on its morphology and 16 S rRNA gene analysis. The effects of initial concentration of TSM,pH,temperature and inoculation size on degradation of TSM were investigated. TSM could be degraded over a broad range of its initial concentration. More than sixty percent of TSM could be degraded when its initial concentration were in the ranged from 5.0 to 100.0 mg·L^-1after incubation for 7 days. The suitable degradation conditions for strain ZWS13 were under 40 ℃,pH 8.0,with 1%（ V / V） of bacteria inoculation. More than99% of TSM was degraded in the concentration of 50.0 mg·L^-1at 40 ℃ after incubation for 10 days. Moreover,strain ZWS13 was capable of degrading nicosulfuron,pyrazosulfuron-ethyl and metsulfuron-methyl. Five degradation byproducts of TSM were identified by using HPLC-MS analysis. The degradation pathways might proceed via C—N bond cleavage of the sulfonylurea bridge,loss of —CH3 from O-demethylation or de-esterification,andcleavage of the triazine ring. The results of present study indicated that strain ZWS13 could effectively degrade TSM and it has potential in bioremediation of soil contaminated by TSM.